Well-drilling apparatus.



A. C. STEWART. WELL DRLLING APPARATUS. APPLIGATION FILED 0c'r.1o, 1911.

1,062,050. Patented May 20, 1913.

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' bit at the bottom of the Well.

ALFRED'C. STEWART, GF LOS AGELES, CALIFGRNIA.

WELL-DRILLNG APPARATUS.

Specification of Letters Patent.

Application filed ctober 10, 1911.

Patented May 2o, 191,3,

Serial N0. 653,959. l

To all when?, it may concern:

Beit knownthat I, ALFRED C. STEWART, a citizen of the United' States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Tell-Drilling Apparatus, of which the following is a specification.

The main object of the invention 'is to provide an apparatus for drilling Wells by power developed and applied at or near the bottom of the well. lil-drilling Wells it has been usual to provide an engine or motor at .the surface and to drive or operate the drilling means by cables, rods or rotary' casings, extending from the surface to the Accor-(linor to my invention, the motor tor operating the bit is located at or near the bottom of the well and is connected directly to the drilling means, theV bit, and motive device theref/or being lowered as the work pro-V gresses.

Another object of the invent-ion is to protect the motive device for the drill from the Water and mud at the bottom ot the Well.

Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate an embodiment of my invention, and referat the. bottom, this caisson being, 'for example, cylindrical and of a size to permit it to pass down through the well casing. Said caisson is supported by a cable or other suspension means el, hung from the usual dei-rick 5 and drum (l at the top of the well. A pipe 7 leads from anair pump H or source of compressed air at the top of the Well and extends down' to the caisson i-S and connects with the interior of said caisson. This' pipe may also be used lor supplying Water for the drilling operation, being connected to a source of water supply, for example, a pump 10.

The drill mechanism is located Within the caisson 3 and operates one'or more bits eX- tending from the caisson at its lowerend. I prefer to use electrically operated drilling means supplied by flexible insulated electric conductors ll, connected to any source of electric current at the top of the well, and extending' down through the Well and connected to the electrically operated motive device Within the caisson. Said electrically operated motive device may consist of solenoids 14. and l5 mounted on a frame `ll3 in caisson 3 and connected to `Wires 11,

the cores 17 and 1S for said solenoids'being,r mounted to slide in guides 2 0 and acting,r as hammers to strike the bits 2l and 522. Said bits 21 and are mounted to slide in guides Q3 and springs 24 and S5 are provided for raisinoq the bits and cores after each operation. lhe number and arrangement of the bits may he varied. l have shown a central bit 2l and a plurality of bits Q2 aroundthe central bit, the operating solenoids being corrcsporulingly disposed, and in order to provide for underreaming to permit free descent of the casing, the outer bits 22 and their operating devices may be arranged with their axes ot' motion'inclined outward so that each bit tends to move outward in -its downward movement.

The opc allen is as follows; The caisson4 is lowered inl'o the well, with the drillingl devices and clcctromolivo means therefor, and'compressed air is supplied to the caisson through pipe 7, so as to exclude water troni lhc caisson or at least from the upper part of the caisson, containingr thc motive dcriccs. lValer may also be supplied llirongfh pipe 7, but said pipe preferably opens at thc lower part of (he caisson, so that such water immediately passes out through the open bottom ol" the caisson and up around the caisson, leaving; the upper parll `ot the caisson clear. T hc motive dericos in the upper part oll thc caisson thcrn- 1 l'ore operate without interference by the wal'cr. The current passing to said motivo devices through wires 1l 1s controlled by any suitable means. so as to produce alternatingg,` or intermittent excitation of the solenoids with reciprocalion of the cores 17 undcr the action ot'thc springs 'lhcse cores so operated act as hammers on the bits 21 and 22, the operation being similar to that of a miningF drill.

By deenergizing all of the solenoids, the

lcnoids and ot' the .cores and bits are forced to raised position by sprin '2 4 and 25, and in this position the bits are rawn inwardly as shown in Fig. 3, sothat the drilling means as a whole, may be drawn up through the casing 2.

What I claim is:

Y 1. Aavell drilling apparatus comprising an open-bottomed caisson, means for lowei' ing and raising said caisson, means -tor supplying compressed air to said caissonto maintain a portionl thereof free of Water,

drilling devices located in said caisson and 'motive means for said drilling devices located adjacent the drilling devices and operating directly thereon.

2. A\Well drillingy apparatus comprising an op'iibottomed caisson, means for lower-v ing and raising said caisson, means for supplying compressed air to said caisson to maintain a portionv thereof free of water,

means for supplying water to said caisson, drilling devices located inthe lower part of said caisson, and motive devices', for said drilling devices located in the Lipper said caisson. f

3. In a well drilling apparatus, van openbottomed caisson, a cable connectedfto said vrreciprocate in said caisson so as to movehi paths inclined to the' vertical, ycutters carpart of caisson, means for operating sadcable for lowering said caisson in the well, drillingl devices in said caisson, electric motive, de 30 ried by said drills and moving'in the opel? Aation of the drills sof-as to projectwhen in their lower positions beyond the -wa-ll of the caisson, and motive means Within the' ca'is- 4 son for operating said drills. t y

In testimony whereof, I have hereuntfs'et iny-hand at Los Angeles, California :this 29th day of September, 1911.

` y ALFRED-o. sTEwiiRrf- In presence of-ey r ARTHUR P. KNIGHT,

- GLADYS RUSSELL.` 

